Entity Framework Core 7 (EF7) Release Candidate 1 has shipped! The team focused on addressing defects, minor enhancements, and putting the finishing touches on features.
Announcing Entity Framework Core 2.2 Preview 2 and the preview of the Cosmos DB provider and spatial extensions for EF Core
مخلص کلام اینکه : اگه با Fody یا PostSharp و همچنین Code Analyzerها آشنایی دارین. این قابلیت یه چیزی تو مایه‌های ترکیب ایناس و بهتون اجازه میده موقع Compile شدن کد پروژه رو Analyze کنین و یه کد جدیدی بهش اضافه کنین. (مثلا پیاده سازی اینترفیس INotifyPropertyChanged به صورت خودکار به هنگام کامپایل)
We’re pleased to introduce the first preview of Source Generators, a new C# compiler feature that lets C# developers inspect user code and generate new C# source files that can be added to a compilation. This is done via a new kind of component that we’re calling a Source Generator.
To get started with Source Generators, you’ll need to install the latest .NET 5 preview and the latest Visual Studio preview.
نمونه ای از پیاده سازی INotifyPropertyChanged with C# 9.0 Source Generators
These are the customer-reported issues addressed in 15.7.3:
/// <summary>
///
/// </summary>
public static class FullTextPrefixes
{
/// <summary>
///
/// </summary>
public const string ContainsPrefix = "-CONTAINS-";
/// <summary>
///
/// </summary>
public const string FreetextPrefix = "-FREETEXT-";
/// <summary>
///
/// </summary>
/// <param name="searchTerm"></param>
/// <returns></returns>
public static string Contains(string searchTerm)
{
return string.Format("({0}{1})", ContainsPrefix, searchTerm);
}
/// <summary>
///
/// </summary>
/// <param name="searchTerm"></param>
/// <returns></returns>
public static string Freetext(string searchTerm)
{
return string.Format("({0}{1})", FreetextPrefix, searchTerm);
}
} public static class FullTextSearchExtensions
{
/// <summary>
///
/// </summary>
/// <typeparam name="TEntity"></typeparam>
/// <param name="source"></param>
/// <param name="expression"></param>
/// <param name="searchTerm"></param>
/// <returns></returns>
public static IQueryable<TEntity> FreeTextSearch<TEntity>(this IQueryable<TEntity> source, Expression<Func<TEntity, object>> expression, string searchTerm) where TEntity : class
{
return FreeTextSearchImp(source, expression, FullTextPrefixes.Freetext(searchTerm));
}
/// <summary>
///
/// </summary>
/// <typeparam name="TEntity"></typeparam>
/// <param name="source"></param>
/// <param name="expression"></param>
/// <param name="searchTerm"></param>
/// <returns></returns>
public static IQueryable<TEntity> ContainsSearch<TEntity>(this IQueryable<TEntity> source, Expression<Func<TEntity, object>> expression, string searchTerm) where TEntity : class
{
return FreeTextSearchImp(source, expression, FullTextPrefixes.Contains(searchTerm));
}
/// <summary>
///
/// </summary>
/// <typeparam name="TEntity"></typeparam>
/// <param name="source"></param>
/// <param name="expression"></param>
/// <param name="searchTerm"></param>
/// <returns></returns>
private static IQueryable<TEntity> FreeTextSearchImp<TEntity>(this IQueryable<TEntity> source, Expression<Func<TEntity, object>> expression, string searchTerm)
{
if (String.IsNullOrEmpty(searchTerm))
{
return source;
}
// The below represents the following lamda:
// source.Where(x => x.[property].Contains(searchTerm))
//Create expression to represent x.[property].Contains(searchTerm)
//var searchTermExpression = Expression.Constant(searchTerm);
var searchTermExpression = Expression.Property(Expression.Constant(new { Value = searchTerm }), "Value");
var checkContainsExpression = Expression.Call(expression.Body, typeof(string).GetMethod("Contains"), searchTermExpression);
//Join not null and contains expressions
var methodCallExpression = Expression.Call(typeof(Queryable),
"Where",
new[] { source.ElementType },
source.Expression,
Expression.Lambda<Func<TEntity, bool>>(checkContainsExpression, expression.Parameters));
return source.Provider.CreateQuery<TEntity>(methodCallExpression);
} public class FtsInterceptor : IDbCommandInterceptor
{
/// <summary>
///
/// </summary>
/// <param name="command"></param>
/// <param name="interceptionContext"></param>
public void NonQueryExecuting(DbCommand command, DbCommandInterceptionContext<int> interceptionContext)
{
}
/// <summary>
///
/// </summary>
/// <param name="command"></param>
/// <param name="interceptionContext"></param>
public void NonQueryExecuted(DbCommand command, DbCommandInterceptionContext<int> interceptionContext)
{
}
/// <summary>
///
/// </summary>
/// <param name="command"></param>
/// <param name="interceptionContext"></param>
public void ReaderExecuting(DbCommand command, DbCommandInterceptionContext<DbDataReader> interceptionContext)
{
RewriteFullTextQuery(command);
}
/// <summary>
///
/// </summary>
/// <param name="command"></param>
/// <param name="interceptionContext"></param>
public void ReaderExecuted(DbCommand command, DbCommandInterceptionContext<DbDataReader> interceptionContext)
{
}
/// <summary>
///
/// </summary>
/// <param name="command"></param>
/// <param name="interceptionContext"></param>
public void ScalarExecuting(DbCommand command, DbCommandInterceptionContext<object> interceptionContext)
{
RewriteFullTextQuery(command);
}
/// <summary>
///
/// </summary>
/// <param name="command"></param>
/// <param name="interceptionContext"></param>
public void ScalarExecuted(DbCommand command, DbCommandInterceptionContext<object> interceptionContext)
{
}
/// <summary>
///
/// </summary>
/// <param name="cmd"></param>
public static void RewriteFullTextQuery(DbCommand cmd)
{
var text = cmd.CommandText;
for (var i = 0; i < cmd.Parameters.Count; i++)
{
var parameter = cmd.Parameters[i];
if (
!parameter.DbType.In(DbType.String, DbType.AnsiString, DbType.StringFixedLength,
DbType.AnsiStringFixedLength)) continue;
if (parameter.Value == DBNull.Value)
continue;
var value = (string)parameter.Value;
if (value.IndexOf(FullTextPrefixes.ContainsPrefix, StringComparison.Ordinal) >= 0)
{
parameter.Size = 4096;
parameter.DbType = DbType.AnsiStringFixedLength;
value = value.Replace(FullTextPrefixes.ContainsPrefix, ""); // remove prefix we added n linq query
value = value.Substring(1, value.Length - 2); // remove %% escaping by linq translator from string.Contains to sql LIKE
parameter.Value = value;
cmd.CommandText = Regex.Replace(text,
string.Format(
@"\[(\w*)\].\[(\w*)\]\s*LIKE\s*@{0}\s?(?:ESCAPE N?'~')", parameter.ParameterName),
string.Format(@"CONTAINS([$1].[$2], @{0})", parameter.ParameterName));
if (text == cmd.CommandText)
throw new Exception("FTS was not replaced on: " + text);
text = cmd.CommandText;
}
else if (value.IndexOf(FullTextPrefixes.FreetextPrefix, StringComparison.Ordinal) >= 0)
{
parameter.Size = 4096;
parameter.DbType = DbType.AnsiStringFixedLength;
value = value.Replace(FullTextPrefixes.FreetextPrefix, ""); // remove prefix we added n linq query
value = value.Substring(1, value.Length - 2); // remove %% escaping by linq translator from string.Contains to sql LIKE
parameter.Value = value;
cmd.CommandText = Regex.Replace(text,
string.Format(
@"\[(\w*)\].\[(\w*)\]\s*LIKE\s*@{0}\s?(?:ESCAPE N?'~')", parameter.ParameterName),
string.Format(@"FREETEXT([$1].[$2], @{0})", parameter.ParameterName));
if (text == cmd.CommandText)
throw new Exception("FTS was not replaced on: " + text);
text = cmd.CommandText;
}
}
}
} public class Note
{
/// <summary>
///
/// </summary>
public int Id { get; set; }
/// <summary>
///
/// </summary>
public string NoteText { get; set; }
}
public class FtsSampleContext : DbContext
{
/// <summary>
///
/// </summary>
public DbSet<Note> Notes { get; set; }
/// <summary>
///
/// </summary>
/// <param name="modelBuilder"></param>
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Configurations.Add(new NoteMap());
}
}
/// <summary>
///
/// </summary>
class Program
{
/// <summary>
///
/// </summary>
/// <param name="args"></param>
static void Main(string[] args)
{
DbInterception.Add(new FtsInterceptor());
const string searchTerm = "john";
using (var db = new FtsSampleContext())
{
var result1 = db.Notes.FreeTextSearch(a => a.NoteText, searchTerm).ToList();
//SQL Server Profiler result ===>>>
//exec sp_executesql N'SELECT
// [Extent1].[Id] AS [Id],
// [Extent1].[NoteText] AS [NoteText]
// FROM [dbo].[Notes] AS [Extent1]
// WHERE FREETEXT([Extent1].[NoteText], @p__linq__0)',N'@p__linq__0
//char(4096)',@p__linq__0='(john)'
var result2 = db.Notes.ContainsSearch(a => a.NoteText, searchTerm).ToList();
//SQL Server Profiler result ===>>>
//exec sp_executesql N'SELECT
// [Extent1].[Id] AS [Id],
// [Extent1].[NoteText] AS [NoteText]
// FROM [dbo].[Notes] AS [Extent1]
// WHERE CONTAINS([Extent1].[NoteText], @p__linq__0)',N'@p__linq__0
//char(4096)',@p__linq__0='(john)'
}
Console.ReadKey();
}
} Today at .NET Conf 2019, we shared some exciting announcements for Xamarin and Visual Studio developers, including:
public class EfRolesService : IRolesService
{
readonly IUnitOfWork _uow;
readonly IDbSet<Role> _roles;
public EfRolesService(IUnitOfWork uow)
{
_uow = uow;
_roles = _uow.Set<Role>();
}
public IList<Role> FindUserRoles(int userId)
{
var query = from role in _roles
from user in role.Users
where user.Id == userId
select role;
return query.OrderBy(x => x.Name).ToList();
}
public string[] GetRolesForUser(int userId)
{
var roles = FindUserRoles(userId);
if (roles == null || !roles.Any())
{
return new string[] { };
}
return roles.Select(x => x.Name).ToArray();
}
public bool IsUserInRole(int userId, string roleName)
{
var query = from role in _roles
where role.Name == roleName
from user in role.Users
where user.Id == userId
select role;
var userRole = query.FirstOrDefault();
return userRole != null;
}
} public class CustomRoleProvider : RoleProvider
{
public override bool IsUserInRole(string username, string roleName)
{
// Since the role provider, in this case the CustomRoleProvider is instantiated by
// the ASP.NET framework the best solution is to use the service locator pattern.
// The service locator pattern is normally considered to be an anti-pattern but
// sometimes you have to be pragmatic and accept the limitation on the framework
// that is being used (in this case the ASP.NET framework).
var rolesService = ObjectFactory.GetInstance<IRolesService>();
return rolesService.IsUserInRole(username.ToInt(), roleName);
}
public override string[] GetRolesForUser(string username)
{
var rolesService = ObjectFactory.GetInstance<IRolesService>();
return rolesService.GetRolesForUser(username.ToInt());
}
// مابقی نیازی نیست پیاده سازی شوند There are two supported choices of runtime for building server-side applications with .NET: .NET Framework and .NET Core. Both share a lot of the same .NET platform components and you can share code across the two. However, there are fundamental differences between the two and your choice will depend on what you want to accomplish. This article provides guidance on when to use each.
